#include<stdio.h>
int main()
{
    float I,W;

    scanf("%f",&I);

    if(I>=0 && I<=10){W = I*0.1;}
    if(I>10 && I<=20){W = 1 + (I-10)*0.075;}
    if(I>20 && I<=40){W = 1.75 + (I-20)*0.05;}
    if(I>40 && I<=60){W = 2.75 + (I-40)*0.03;}
    if(I>60 && I<=100){W = 3.95 + (I-60)*0.015;}
    if(I>100){W = 4.55 + (I-100)*0.01;}

    printf("%.3f",W);

    return 0;
}